Heterojunction is an interface region formed by a contact of two different semiconductor materials. According to the conductivity types of different semiconductor materials, the heterojunction can be divided into homogeneous heterojunction (P-p junction or N-n junction) and heterotypic heterojunction (P-n or p-N). A heterostructure can be formed by multilayer heterojunctions. The heterostructure has excellent photoelectric properties, thus semiconductor devices being made of the heterostructure also have excellent photoelectric properties.
However, the heterogeneous structures of conventional semiconductor devices are usually microstructures, applications of the semiconductor devices are limited.